In conventional switch devices that perform a switch operation of switching on/off of information based on a pressing-down operation by a user, the switch operation is performed by utilizing a reaction force against the pressing-down operation with, for example, an elastic sheet-like rubber plate (Patent Document 1, for example) and a sheet with a swollen portion (Patent Document 2, for example).
For example, the switch device disclosed in Patent Document 1 is provided with a switch having a metal plate contact point that is protruded via an elastic member such as synthetic rubber. The switch has a configuration in which when a corresponding key button directly above the elastic member is pressed down in a switch operation, the metal plate contact point is flattened, thereby turning the switch on, for example. On the other hand, when the pressing-down force on the key button is removed, a restoring force of the elastic member and the metal plate contact point returns the metal plate contact point to its original shape, thereby turning the switch off, for example.
Furthermore, the switch device disclosed in Patent Document 2 has a configuration in which when a swollen portion provided on a sheet is pressed with a finger of a user in a switch operation, the swollen portion is dented downward, and a head portion of a switch group disposed therebelow is pressed downward, thereby turning the switch on.
In addition to the above-described switch devices in which a pressing-down operation is necessary in a switch operation, a so-called touch-switch is known in which when contact with a user is detected, the switch operation is performed (Patent Document 3, for example).
More specifically, in the touch switch disclosed in Patent Document 3, the contact of a user with a touch panel is detected when the capacitance of a touch detection electrode changes and reaches a predetermined threshold value or less, or the capacitance that is a predetermined threshold value or less is kept for a predetermined time or more.
Patent Document 1: JP 2003-347757A (see paragraphs 0026 to 0029, for example)
Patent Document 2: JP 2003-47797A (see paragraph 0018, for example)
Patent Document 3: Japanese Patent No. 3480276 (see paragraphs 0002 to 0006, for example)